This invention relates to a vertical autoclave for bulk preparation of vinyl chloride based copolymers and polymers. It also relates to a method of preparation, in bulk, of vinyl chloride based polymers and copolymers which employs said autoclave.
It has already been suggested to effect preparation in bulk, of vinyl chloride polymers and copolymers in two stages carried out in different vessels by a method consisting of carrying out, in the first stage, a limited polymerization, known as prepolymerization, with agitation at high turbulence, until a conversion of the monomer or monomers of the order of 7% to 15% is achieved, then to effect, in a second stage, a final polymerization operation under low agitation, the speed of agitation in this step however remaining sufficient to maintain the temperature of the reaction medium substantially uniform until the end of the polymerization or copolymerization reaction.
This process and variatiions thereon have been described in French Patents and Certificates of Addition Nos. 1,382,072, 84,958, 84,965, 84,966, 85,672, 89,025 and Nos. 1,436,744, 87,620, 87,623, 87,625, 87,626.